The present invention relates to a magnet driving method for driving a plurality of magnets to provide a predetermined process for a work to be processed in a vacuum chamber, and to a device for same.
In general, as an equipment, provided with such a magnet driving device, there is a sputtering equipment as will as a dry etching equipment employed in the production of electronic elements or semiconductors.
In a conventional sputtering equipment, a target is placed on a target support plate having therein water-cooling pipes in a vacuum chamber. At the underside of the target support plate are disposed coaxially a plurality of magnets which are rotated eccentrically about an eccentric shaft. A plasma discharge is induced on the target by a magnetic field formed by the magnets.
However, in this conventional equipment, since the magnets are eccentrically rotated, the strength of the magnetic field is not uniform over the entire region of the target. Thus, in those areas of the target on which a strong magnetic field is generated, its material is sputtered, forming recesses, while in the remaining areas thereof where a weak magnetic field is generated, its material is left without sputtering. As a result, in the sputtering process, the material of the target is not uniformly spattered, thus confronting with disadvantages such that a failure to achieve an effective use of material raises the sputtering process cost.
Further, in a conventional dry etching equipment, a magnet in a slender form longer than the outer diameter of a wafer placed on an electrode in a vacuum chamber is moved forward and backward through a stroke beyond the outer diameter of the wafer.
In this dry etching equipment, a magnetic field of the magnet uniformly acts over the entirety of the wafer, thus permitting a uniform etching by a plasma discharge to be effected over the wafer.
However, in order that the magnetic field uniformly acts on the wafer, the magnet must be moved to opposite positions over a region of the wafer. While the magnet is positioned outside the wafer like above, the magnetic field does not act on the wafer. This inactive time period of the magnetic field is considerably long, thus resulting in a disadvantage that a long time is consumed for completion of the etching.